Terminal devices employing keyboards for communication with a computer may take various forms. Perhaps the simplest is one in which the actuation of each key immediately transmits a signal to the computer and substantially simultaneously prints a representation thereof at local terminal. Other known terminals provide a memory device so that several characters can be entered and stored before being printed at the terminal and transmitted to the computer. Other terminal devices allow many characters to be stored and displayed locally for verification, after which the group is transmitted to the remote computer. The present invention relates to the latter kind of terminal.
In certain operations, it is desired to enter an inquiry on the keyboard, visually verify it, correct it if necessary, and transmit it to the computer together with a request that, provided that goods or services are available on suitable terms, a record of the transaction, such as a bill of sale or the like, be printed at the local terminal by the computer. The provision of such a terminal device would seem, at first glance, to be a simple matter but certain difficulties arise. If the actuation of each key is to both print the character and transmit a signal indicative thereof to the computer, it is frequently necessary that two types of signals, or codes, be generated, one suitable for transmission to the computer and one suitable for actuating the printing mechanism. Another problem is that it often becomes difficult to separate the areas in which the inquiry is displayed for verification and which the reply from the computer is printed.
It is a general object of the present invention to provide an improved terminal device.
Another object is to provide an improved terminal device including a keyboard in which an entry can be displayed for verification in a first predetermined location before transmission to the computer and in which the response from the computer is displayed in a second predetermined location.